Zephel is a 17-year-old male with platinum hair and ruby-red eyes, standing 169cm tall—later adjusted to 171cm in certain continuities—and weighing 51kg, increasing to 53kg in later appearances. Born June 4 under the Gemini sign with blood type B, he hails from an industrial planetoid belt. His father, a factory engineer, rooted Zephel in a commoner lineage and early mechanical exposure. At age 16, he became a Guardian wielding the Sacrea of "Steel," channeling technology for metal and mineral processing.

His personality merges rebelliousness with latent gentleness, marked by a strong affinity for machinery and technical tinkering. Hobbies include rollerblading, squash, and mechanical engineering, with focused interests in nanomachines and environmental topics. He shares a close bond with Luva but frequently clashes with Randy, dubbing him his "worst friend."

Zephel harbors unresolved romantic feelings for Ange. His preferences reflect practicality: favoring mineral water, chicken curry, tacos, and soap scent, while disliking jam, fresh cream, salad fruits, and candy. He envisions an "average girl" as his ideal partner and cherishes cats alongside mechanical engineering books.

Appearing across Angelique OVAs and television series—including Angelique: Twin Collection episode 3—Zephel maintains consistent design and core traits. His narrative emphasizes his Guardian of Steel role, technical aptitude, and relational dynamics, without significant backstory evolution.